Plants provide food to people and animals, regulate the water cycle, create oxygen and provide a habitat for other species. Without plants, life on Earth would not be sustainable for most species, including humans.
In addition to regulating the water cycle, plants also help purify the planet's water, which is important to sustain life. Plants and trees create oxygen through a process called photosynthesis. A decrease in plants and trees means a decrease in oxygen, which humans and other species require in order to breathe. These things aside, plants are also used for medicinal purposes. Many plants have healing properties, and one-quarter of prescription drugs come from plants. Plants also store carbon, which is a fact that helps keep carbon dioxide out of the atmosphere.